Our current understanding of hematopoietic stem cell differentiation and the abnormalities that lead to leukemogenesis originates from the accumulation of knowledge regarding protein-coding genes. However, the possible impact of transposable element (TE) mobilization and the expression of P-element-induced WImpy testis-interacting RNAs (piRNAs) on leukemogenesis has been beyond the scope of scientific interest to date. The expression profiles of these molecules and their importance for human health have only been characterized recently due to the rapid progress of high-throughput sequencing technology development. In the present review, current knowledge on the expression profile and function of TEs and piRNAs was summarized, with specific focus on their reported involvement in leukemogenesis and pathogenesis of myelodysplastic syndrome.

• MeSH
• lidé MeSH
• malá interferující RNA genetika   MeSH
• myelodysplastické syndromy genetika   patologie   MeSH
• transpozibilní elementy DNA * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

To better understand the molecular basis of resistance to azacitidine (AZA) therapy in myelodysplastic syndromes (MDS) and acute myeloid leukemia with myelodysplasia-related changes (AML-MRC), we performed RNA sequencing on pre-treatment CD34+ hematopoietic stem/progenitor cells (HSPCs) isolated from 25 MDS/AML-MRC patients of the discovery cohort (10 AZA responders (RD), six stable disease, nine progressive disease (PD) during AZA therapy) and from eight controls. Eleven MDS/AML-MRC samples were also available for analysis of selected metabolites, along with 17 additional samples from an independent validation cohort. Except for two patients, the others did not carry isocitrate dehydrogenase (IDH)1/2 mutations. Transcriptional landscapes of the patients' HSPCs were comparable to those published previously, including decreased signatures of active cell cycling and DNA damage response in PD compared to RD and controls. In addition, PD-derived HSPCs revealed repressed markers of the tricarboxylic acid cycle, with IDH2 among the top 50 downregulated genes in PD compared to RD. Decreased citrate plasma levels, downregulated expression of the (ATP)-citrate lyase and other transcriptional/metabolic networks indicate metabolism-driven histone modifications in PD HSPCs. Observed histone deacetylation is consistent with transcription-nonpermissive chromatin configuration and quiescence of PD HSPCs. This study highlights the complexity of the molecular network underlying response/resistance to hypomethylating agents.

• Publikační typ
• časopisecké články MeSH

Congenital hypofibrinogenemia is a rare bleeding disorder characterized by a proportional decrease of functional and antigenic fibrinogen levels. Hypofibrinogenemia can be considered the phenotypic expression of heterozygous loss of function mutations occurring within one of the three fibrinogen genes (FGA, FGB, and FGG). Clinical manifestations are highly variable; most patients are usually asymptomatic, but may appear with mild to severe bleeding or thrombotic complications. We have sequenced all exons of the FGA, FGB, and FGG genes using the DNA isolated from the peripheral blood in two unrelated probands with mild hypofibrinogenemia. Coagulation screening, global hemostasis, and functional analysis tests were performed. Molecular modeling was used to predict the defect of synthesis and structural changes of the identified mutation. DNA sequencing revealed a novel heterozygous variant c.1421G>A in exon 8 of the FGB gene encoding a Bβ chain (p.Trp474Ter) in both patients. Clinical data from patients showed bleeding episodes. Protein modelling confirmed changes in the secondary structure of the molecule, with the loss of three β sheet arrangements. As expected by the low fibrinogen levels, turbidity analyses showed a reduced fibrin polymerisation and imaging difference in thickness fibrin fibers. We have to emphasize that our patients have a quantitative fibrinogen disorder; therefore, the reduced function is due to the reduced concentration of fibrinogen, since the Bβ chains carrying the mutation predicted to be retained inside the cell. The study of fibrinogen molecules using protein modelling may help us to understand causality and effect of novel genetic mutations.

• Publikační typ
• časopisecké články MeSH

Circular RNAs (circRNAs) constitute a recently recognized group of noncoding transcripts that function as posttranscriptional regulators of gene expression at a new level. Recent developments in experimental methods together with rapidly evolving bioinformatics approaches have accelerated the exploration of circRNAs. The differentiation of hematopoietic stem cells into a broad spectrum of specialized blood lineages is a tightly regulated process that depends on a multitude of factors, including circRNAs. However, despite the growing number of circRNAs described to date, the roles of the majority of them in hematopoiesis remain unknown. Given their stability and disease-specific expression, circRNAs have been acknowledged as novel promising biomarkers and therapeutic targets. In this paper, the biogenesis, characteristics, and roles of circRNAs are reviewed with an emphasis on their currently recognized or presumed involvement in hematopoiesis, especially in acute myeloid leukemia and myelodysplastic syndrome.

• MeSH
• akutní myeloidní leukemie krev   genetika   MeSH
• hematopoéza * MeSH
• kruhová RNA krev   genetika   MeSH
• lidé MeSH
• myelodysplastické syndromy krev   genetika   MeSH
• nádorové biomarkery krev   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Omega-3 polyunsaturated fatty acids (ω-3PUFAs) are introduced into parenteral nutrition (PN) as hepatoprotective but may be susceptible to the lipid peroxidation while olive oil (OO) is declared more peroxidation resistant. We aimed to estimate how the lipid composition of PN mixture affects plasma and erythrocyte lipidome and the propensity of oxidative stress. A cross-sectional comparative study was performed in a cohort of adult patients who were long-term parenterally administered ω-3 PUFAs without (FO/-, n = 9) or with (FO/OO, n = 13) olive oil and healthy age- and sex-matched controls, (n = 30). Lipoperoxidation assessed as plasma and erythrocyte malondialdehyde content was increased in both FO/- and FO/OO groups but protein oxidative stress (protein carbonyls in plasma) and low redox status (GSH/GSSG in erythrocytes) was detected only in the FO/- subcohort. The lipidome of all subjects receiving ω-3 PUFAs was enriched with lipid species containing ω-3 PUFAs (FO/-˃FO/OO). Common characteristic of all PN-dependent patients was high content of fatty acyl-esters of hydroxy-fatty acids (FAHFAs) in plasma while acylcarnitines and ceramides were enriched in erythrocytes. Plasma and erythrocyte concentrations of plasmanyls and plasmalogens (endogenous antioxidants) were decreased in both patient groups with a significantly more pronounced effect in FO/-. We confirmed the protective effect of OO in PN mixtures containing ω-3 PUFAs.

• MeSH
• antioxidancia metabolismus   MeSH
• dospělí MeSH
• erytrocyty metabolismus   MeSH
• kyseliny mastné omega-3 farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lipidomika MeSH
• lipidy krev   MeSH
• nemoci střev krev   terapie   MeSH
• olivový olej farmakologie   MeSH
• oxidační stres účinky léků   MeSH
• parenterální výživa škodlivé účinky   metody   MeSH
• průřezové studie MeSH
• rybí oleje farmakologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• tukové emulze intravenózní farmakologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Identification and quantitative monitoring of mutant BCR-ABL1 subclones displaying resistance to tyrosine kinase inhibitors (TKIs) have become important tasks in patients with Ph-positive leukemias. Different technologies have been established for patient screening. Various next-generation sequencing (NGS) platforms facilitating sensitive detection and quantitative monitoring of mutations in the ABL1-kinase domain (KD) have been introduced recently, and are expected to become the preferred technology in the future. However, broad clinical implementation of NGS methods has been hampered by the limited accessibility at different centers and the current costs of analysis which may not be regarded as readily affordable for routine diagnostic monitoring. It is therefore of interest to determine whether NGS platforms can be adequately substituted by other methodological approaches. We have tested three different techniques including pyrosequencing, LD (ligation-dependent)-PCR and NGS in a series of peripheral blood specimens from chronic myeloid leukemia (CML) patients carrying single or multiple mutations in the BCR-ABL1 KD. The proliferation kinetics of mutant subclones in serial specimens obtained during the course of TKI-treatment revealed similar profiles via all technical approaches, but individual specimens showed statistically significant differences between NGS and the other methods tested. The observations indicate that different approaches to detection and quantification of mutant subclones may be applicable for the monitoring of clonal kinetics, but careful calibration of each method is required for accurate size assessment of mutant subclones at individual time points.

• MeSH
• bcr-abl fúzové proteiny chemie   genetika   MeSH
• chronická myeloidní leukemie genetika   patologie   MeSH
• DNA analýza   genetika   metabolismus   MeSH
• lidé MeSH
• polymerázová řetězová reakce * MeSH
• sekvenční analýza DNA * MeSH
• srovnávací genomová hybridizace MeSH
• vysoce účinné nukleotidové sekvenování * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

We present a retrospective analysis of 137 patients with early MDS without excess of blasts that revealed transfusion dependency in 87% of the cases. A significant difference in overall survival was noted between patients receiving 2 units of RBC transfusions/month (65.0 vs. 35.3 months, respectively, P=0.02). Univariate statistical analysis identified the presence of disease progression to advanced MDS (chi(2)=26.4, P=0.001) and the administration of >1 or >2 units of RBC per month (chi(2)=15.9 and 14.6, respectively, P=0.001) as the most important parameters affecting survival. Nevertheless, even the administration of 1 RBC unit every 4-8 weeks had a significantly adverse impact on survival compared to non-transfused patients. Transfusion dependency itself did not affect disease progression as determined by the presence of multilineage dysplasia and adverse karyotype (expressed by the IM-1 or IM-2 score). Multivariate analysis confirmed disease progression towards leukemia as a highly significant independent variable affecting survival (P=0.0001). None of the other evaluated parameters had a significant impact on survival in patients with progressive disease. In non-transplanted patients without MDS progression, administration of >2 units of RBC transfusions/month was the only independent variable with adverse impact on survival in patients with unilineage erythroid dysplasia (P=0.02). In patients with multilineage dysplasia, only heavy transfusion dependency (>3TURBC/month) and serum ferritin >2000 microg/l adversely affected survival (P=0.03). Modification of the WPSS by replacing transfusion dependency with initial Hb level <80 g/l retained its prognostic relevance and allowed the identification of a potential risk subset of early MDS patients with intermediate and high scores and limited survival (<40% at 5 years) as early as at the time of diagnosis. Our results confirm a significant negative impact of transfusion dependency on survival in patients with early MDS without excess of blasts. The main risk subgroup is characterized by unilineage dysplasia limited to erythropoiesis in combination with dependency on >2TU of RBC per month. These patients usually have prolonged survival that leads to the development of heavy transfusion iron overload and they thus represent the most important target group for intensive chelation therapy.

• MeSH
• analýza přežití MeSH
• krevní transfuze MeSH
• lidé MeSH
• myelodysplastické syndromy patologie   terapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH